rockbox/firmware/target/arm/as3525/dbop-as3525.c
Rafaël Carré 57667c51cf Sansa AMS: refactor DBOP button reading (e200v2/Fuze/c200v2)
This gets rid of LCD glitches on Sansa Fuze, and now LCD transfers can
get interrupted by button reading

Flyspray: FS #10603
Author: Bertrik Sikken

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@24192 a1c6a512-1295-4272-9138-f99709370657
2010-01-06 23:41:36 +00:00

77 lines
2.6 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2009 by Bertrik Sikken
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "config.h"
#include "as3525.h"
#include "dbop-as3525.h"
#if defined(SANSA_FUZE)
#define DBOP_PRECHARGE 0x80FF
#elif defined(SANSA_E200V2) || defined(SANSA_C200V2)
#define DBOP_PRECHARGE 0xF0FF
#endif
static short int dbop_input_value = 0;
/* read the DBOP data pins */
unsigned short dbop_read_input(void)
{
unsigned int dbop_ctrl_old = DBOP_CTRL;
unsigned int dbop_timpol23_old = DBOP_TIMPOL_23;
/* make sure that the DBOP FIFO is empty */
while ((DBOP_STAT & (1<<10)) == 0);
/* write DBOP_DOUT to pre-charge DBOP data lines with a defined level */
DBOP_TIMPOL_23 = 0xe007e007; /* no strobe towards lcd */
int delay = 10;
while (delay--) asm volatile ("nop\n");
DBOP_CTRL = (1 << 19) | /* tri-state output */
(1 << 16) | /* enw=1 (enable write) */
(1 << 12); /* ow=1 (16-bit data width) */
DBOP_DOUT = DBOP_PRECHARGE;
while ((DBOP_STAT & (1<<10)) == 0);
#if defined(SANSA_FUZE) || defined(SANSA_E200V2)
delay = 50;
while (delay--) asm volatile ("nop\n");
#endif
/* perform a DBOP read */
DBOP_CTRL = (1 << 19) | /* tri-state output */
(1 << 15) | /* strd=1 (start read) */
(1 << 12) | /* ow=1 (16-bit data width) */
(31 << 0); /* rs_t=31 (read DBOP at end of cycle) */
while ((DBOP_STAT & (1<<16)) == 0);
dbop_input_value = DBOP_DIN;
/* restore previous values */
DBOP_TIMPOL_23 = dbop_timpol23_old;
DBOP_CTRL = dbop_ctrl_old;
return dbop_input_value;
}
/* for the debug menu */
unsigned short dbop_debug(void)
{
return dbop_input_value;
}